ABSTRACT
This research was done to evaluate the feasibility of using Albizia procera for manufacturing glulam beams. The physical and mechanical properties of the A. procera glulam beam were evaluated, and these properties were compared to those of the solid A. procera solid timber. The A. procera glulam beam's physical and mechanical properties were all superior to solid A. procera timber. In comparison to A. procera solid timber, A. procera glulam's density, water absorption (WA), linear expansion (LE), and thickness swelling (TS) all improved by 11.1, 48.4, 44.6, and 37.0%, respectively. Again, compared to A. procera solid timber, the modulus of rupture (MOR) and modulus of elasticity (MOE) of the A. procera glulam beam increased by 27.6 and 29.2%, respectively. Additionally, the ASTM specifications were met by the A. procera glulam beam. As a result, based on the properties, it is possible to make A. procera glulam beams as structural timber products.
ABSTRACT
The growing demand for energy and environmental issues are the main concern for the sustainable development of modern society. Replacing toxic and expensive materials with inexpensive and biodegradable biomaterials is the main challenge for researchers. Nanocomposites are of the utmost consideration for their application in energy storage devices because of their specific electrochemical properties. Cellulose-based bionanocomposites have added a new dimension to this field since these are developed from available renewable biomaterials. Studies on developing electrodes, separators, collectors, and electrolytes for the batteries have been conducted based on these composites rigorously. Electrodes and separators made of these composites for the supercapacitors have also been investigated. Researchers have used a wide range of micro- and nano-structural cellulose along with nanostructured inorganic materials to produce cellulose-based bionanocomposites for energy devices, i.e., supercapacitors and batteries. The presence of cellulosic materials enhances the loading capacity of active materials and uniform porous structure in the electrode matrix. Thus, it has shown improved electrochemical properties. Therefore, these can help to develop biodegradable, lightweight, malleable, and strong energy storage devices. In this review article, the manufacturing process, properties, applications, and possible opportunities of cellulose-based bionanocomposites in energy storage devices have been emphasized. Its challenges and opportunities have also been discussed.
ABSTRACT
Melocanna baccifera is the most common bamboo species which grows naturally and gregariously covering large tracts of land in the forests of Chittagong Hill Tracts of Bangladesh. However, there is limited information about the chemical characterization of its culms for its utilization and processing. This paper aimed to determine the effect of age and height position on the chemical properties of M. baccifera. The highest value of holocellulose content was 74.66% for the top portion of 3-year-old bamboo, while the bottom part of 3-year-old bamboo showed the highest value of lignin (27.83%) and extractive (5.24%) content. For caustic soda (1% NaOH) solubility, the bottom portion of 1-year-old bamboo had shown the maximum value (25.67%), and it was the lowest (19.10%) for the top portion of 3-year-old bamboo. Ageing had a significant (p < 0.05) effect on all chemical properties, while the height position had a significant effect on the holocellulose and lignin content and water solubility. The chemical properties of M. baccifera can enable its proper utilization in the downstream process.
ABSTRACT
Anthocephalus chinensis (Lam.) A. Rich ex Walp is widely used as raw materials in particleboard and match industries in Bangladesh. The current study aimed to identify the drying characteristics of A. Chinensis wood for succeeding industrial usages. A compartment kiln dryer (heat and vent dryer) was used in this study. The drying characteristics and drying quality of A. Chinensis wood were measured. The boards reached 6-10% moisture content in 13 days from their green condition. The total proportions of the check, twist, and collapse in boards were 22.5, 32.5, and 7.3%, respectively. The volumetric shrinkage was 21.67%. Based on this study, further study may help to develop a complete drying schedule of A. Chinensis wood with fewer drying defects for application at industrial level.
ABSTRACT
Background: Understanding the spirometry-based prevalence with concomitant assessment of the health status is important to appreciate the chronic obstructive pulmonary disease (COPD)-scenario in a geographic area. There is hardly any such rural data available from the developing world. Methods: We screened the adult population (>40 but <75 years) of seven villages in two different blocks of Birbhum district, West Bengal, for the presence respiratory symptoms (active or historical within 1 year). Those screened positive were tested with spirometry to diagnose COPD on having post bronchodilator FEV1/FVC <0.7. The COPD subjects were then applied with COPD assessment test (CAT). Results: Out of 6255 subjects residing in the villages, 1984 subjects belonged to the target age group and 51.56% (1013 of 1984) of them qualified for spirometry which was possible in 953 (88.81%) of them. COPD was identified in 166 (16.36%) of symptomatic individuals. The calculated prevalence of COPD was 2.65% in overall population and 8.367% in population above 40 years. The COPD patients (mean age 59.77 ± 9.47 years) had a male preponderance (120 [72.29%] of 166). They were mostly malnourished (body mass index = 17.15 ± 2.97), with poorhealth status (CAT = 15) and moderate degree (GOLD category-II) of airflow limitation showing FEV1/FVC as 0.60 ± 0.07 and the mean post bronchodilator FEV1 as 52% of predicted (1.26 ± 0.42 L). Most of the sufferers (74.09%) were either active (n = 88) or ex-smokers (n = 35) (>10 pack-years). The nonsmokers constituted 25, 90% (n = 43). Conclusion: The rural COPD prevalence in Bengal is far higher than the estimated national average with the health status of the sufferers been poor.
ABSTRACT
BACKGROUND: Rehabilitation has been an integral part of management of COPD. Since the implementation of the standard rehabilitation protocol is hardly possible in the rural developing world, aiming to make a feasible alternate effort may be worthwhile. METHODS: COPD patients diagnosed through spirometry were first stabilized with 6 weeks of uniform pharmacotherapy. Subsequently, they were subjected to a curriculum-based intensive single-session intervention with education, bronchial hygiene, and exercise training. The latter involved whole body exercise, pursed lip breathing, and diaphragmatic exercise. The participants continued to practice the exercises under real-world encouragement and supervision from trained volunteers. The impact was appraised in terms of change in health status through COPD assessment test (CAT) score measurements at stabilization, and after 6 weeks and 1 year of the intensive training and education. RESULTS: At stabilization, 70 out of 96 selected COPD subjects (73%) turned up (with mean age 62±9 years and mean FEV1 as 1.16±0.39 L) showing improvement as per CAT score (p=0.0001) from pharmacotherapy. After practicing the imparted education and training for 6 weeks, all these 70 participants had further significant improvement in the health status (n=70, p=0.00001). This improvement, been reinforced and supervised, continued to last even at 1 year (n=54, p=0.0001). CONCLUSION: The self-managed practice of a single-session education and training under real-world supervision can bring forth significant long-term improvement in the health status of COPD sufferers. Such simple and feasible intervention may substitute formal COPD rehabilitation programs in resource constraint situations.
